To link to the entire object, paste this link in email, IM or documentTo embed the entire object, paste this HTML in websiteTo link to this page, paste this link in email, IM or documentTo embed this page, paste this HTML in website

Bryozoa of the Pacific coast of America

Bryozoa of the Pacific coast of America, Barentsia subrigida, new species, p. 770

770 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14
Barentsia subrigida new species
Plate 82, fig. 9
A large species, reaching a height of more than 5 mm; it is especially
characterized by the stalk which possesses regularly two internodes; the
basal one is very elongate, 1.30 to more than 4 mm; the basal half, more
or less, has the wall chitinized and rigid while the upper part remains
thin-walled, muscular and flexible; this is followed by a somewhat expanded muscular joint, and above this is a short thin-walled and wrinkled
flexible internode, only 0.40 to 0.55 mm in length. When completely
developed, the top of the basal internode and the base of the terminal
internode are both enlarged to about twice the width of the stem with
a short muscular section between them; the terminal one has a definite
diaphragm just above the node, similar to the one at the base of the
first internode. Very old basal internodes may become chitinized for
the full length, but I have seen only two such internodes. In any case
the short terminal internode is always transparent and flexible. The
basal internode usually bears a few "perforations," scattered and generally disappearing entirely on the upper half.
The basal muscular bulb varies greatly in height, from 0.25 to 0.55
mm, probably depending on the nature of contraction, and the width
is about 0.15 mm.
The calyx is large, averaging about 0.35 mm high to the base of the
tentacle crown, by 0.40 mm in width; the largest calyx measures 0.50
mm high by 0.52 mm wide; the dorsal side is more rounded than the
frontal side, and the base is broadly rounded and attached by a rounded
bulb to the upper internode. The tentacle number cannot be counted
accurately but it appears to be at least 20.
The very regular disparity in the length of the two internodes, the
thin-walled flexible upper ends of the basal internodes and the constant
thin-walled, muscular, short terminal internodes, together with the large
size, apparently mark this as a hitherto unknown species. It is possible
that the Ascopodaria macropus of Robertson may belong here instead
of under B. geniculata. The only other known species with flexible internodes is B. laxa Kirkpatrick, which has no joints in the stalk, no "perforations," and the stalk is not heavily chitinized basally.
Type, AHF no. 132.
Type locality, Hancock Station 1274-41, three and one-half miles
south of Hueneme, southern California, 28°23'20"N, 115°11'52"W,
at 55 fms, two colonies. Another specimen in the collection is labeled
simply "California."

770 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14
Barentsia subrigida new species
Plate 82, fig. 9
A large species, reaching a height of more than 5 mm; it is especially
characterized by the stalk which possesses regularly two internodes; the
basal one is very elongate, 1.30 to more than 4 mm; the basal half, more
or less, has the wall chitinized and rigid while the upper part remains
thin-walled, muscular and flexible; this is followed by a somewhat expanded muscular joint, and above this is a short thin-walled and wrinkled
flexible internode, only 0.40 to 0.55 mm in length. When completely
developed, the top of the basal internode and the base of the terminal
internode are both enlarged to about twice the width of the stem with
a short muscular section between them; the terminal one has a definite
diaphragm just above the node, similar to the one at the base of the
first internode. Very old basal internodes may become chitinized for
the full length, but I have seen only two such internodes. In any case
the short terminal internode is always transparent and flexible. The
basal internode usually bears a few "perforations," scattered and generally disappearing entirely on the upper half.
The basal muscular bulb varies greatly in height, from 0.25 to 0.55
mm, probably depending on the nature of contraction, and the width
is about 0.15 mm.
The calyx is large, averaging about 0.35 mm high to the base of the
tentacle crown, by 0.40 mm in width; the largest calyx measures 0.50
mm high by 0.52 mm wide; the dorsal side is more rounded than the
frontal side, and the base is broadly rounded and attached by a rounded
bulb to the upper internode. The tentacle number cannot be counted
accurately but it appears to be at least 20.
The very regular disparity in the length of the two internodes, the
thin-walled flexible upper ends of the basal internodes and the constant
thin-walled, muscular, short terminal internodes, together with the large
size, apparently mark this as a hitherto unknown species. It is possible
that the Ascopodaria macropus of Robertson may belong here instead
of under B. geniculata. The only other known species with flexible internodes is B. laxa Kirkpatrick, which has no joints in the stalk, no "perforations," and the stalk is not heavily chitinized basally.
Type, AHF no. 132.
Type locality, Hancock Station 1274-41, three and one-half miles
south of Hueneme, southern California, 28°23'20"N, 115°11'52"W,
at 55 fms, two colonies. Another specimen in the collection is labeled
simply "California."